Hermann Fritzsche

Bio: Hermann Fritzsche is an academic researcher from Society of Chemical Industry. The author has an hindex of 2, co-authored 2 publications receiving 10 citations.

Tris and polyazo dyes from tetrazotized 0:0' dihydroxybenzidine

Abstract: The present invention is concerned with valuable new tris- and poly-azo-dyestuffs, and a process for preparing the same. The present invention is particularly concerned with direct dyeing cotton dyestuffs (also called substantive dyestuffs), and still more particularly with dyestuffs capable...

Metallized benzimidazole azo dyestuffs

Abstract: This invention relates to metallized azo dyestuffs. More particularly, it relates to metal complexes of azo dyestuffs with metals of atomic weight from 52-64, represented by the following formula: NH in which R is hydrogen, mononuclear aryl or lower alkyl and A is the residue of a diazotized...

Disazo dye from dihydroxy benzidine and process therefor

Abstract: According to this invention valuable asymmetrical disazo-dyestuffs are .made by coupling tetrazottsed 8:8'-dihydroxy-4:4'-dlaminodiphensy with coupling components, and conducting the first coupling operation in a reaction medium having a pH value ranging from that of an acetic acid medium to...

Metallizable polyazo dyes from benzidine intermediates

Abstract: It has been found that valuable copperable polyazo dyestuffs are obtained by combining tetrazotised 4:4'-diamino-3: 3'-dialkoxydiphenyl compounds, the alkoxy groups of which may also be substituted, in any suitable order of succession with 1-molecule of an aminoazo dyestuff, which is obtainable...

Metallizable benzimidazole azo dyestuffs

Abstract: This invention relates to metallizable azo dyestuffs having lake-forming groups ortho to the azo group derived from 5-hydroxy-benzimidazoles. The products may be represented by the following formula: N HOr 3 2C-R A-N=N6- \ in which R is hydrogen or a radical of the benzene or lower aliphatic...